Portable platform



FIG. 1 is a front perspective view of a portable platform showing my new design;

FIG. 2 is a top plan view;

FIG. 3 is a front elevational view;

FIG. 4 is a right side elevational view;

FIG. 5 is a left side elevational view;

FIG. 6 is a bottom plan view; and

FIG. 7 is a rear elevational thereof. 

The ornamental design for the portable platform, as shown and described. 